life is very c( )in a tall builing with the help of the lift

life is very c( )in a tall builing with the help of the lift
life is very c( )in a tall builing with the help of the lift

life is very c( )in a tall builing with the help of the lift
convenient

convenient 方便的 句意：有了电梯的帮助，大楼里的生活十分方便